Developmental and genetic mechanisms of tissue identity and patterning

组织身份和模式的发育和遗传机制

• 批准号: 8945728
• 负责人: Michael David Shapiro
• 金额: $ 29.43万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8945728
• 关键词: Alleles; Animals; Biological; Biological Assay; Biological Models; Biology; Breeding; Candidate Disease Gene; ChIP-seq; Chickens; Chromatin; Chromosome Mapping; Columbidae; Complex; Congenital Abnormality; Congenital clubfoot; DNA Resequencing; DNA Sequence; DNA Structure; Defect; Deformity; Dermal; Development; Developmental Biology; Disease; Down-Regulation; Ectopic Expression; Embryo; Embryonic Development; Employee Strikes; Enhancers; Evolution; Feathers; Forelimb; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genome; Genomics; Goals; Health; High-Throughput RNA Sequencing; Hindlimb; Holt Oram syndrome; Human; Hybrids; Infertility; Lead; Leg; Limb Development; Limb structure; Maps; Molecular; Morphology; Muscle; Mutation; Noise; Organ; Pattern; Phenotype; Phylogenetic Analysis; Program Development; Quantitative Trait Loci; Regulation; Regulator Genes; Relative (related person); Reporter; Repression; Resources; Rock Pigeons; Role; Signal Transduction; Skin; Skin Tissue; Specific qualifier value; Syndrome; System; Tendon structure; Testing; Time; Tissues; To specify; Variant; Vertebrates; appendage; base; developmental genetics; differential expression; embryonic tissue transplantation; foot; gene function; genome wide association study; innovation; insight; interest; malformation; mutant; public health relevance; research study; trait; vertebrate genome

 DESCRIPTION (provided by applicant): Understanding the molecular basis of anatomical variation is a fundamental challenge in biology. In some cases, the genes that control anatomical defects in humans instead underlie normal variation in other species; therefore, a comprehensive understanding of the general molecular mechanisms of diversity promises greater insights about human health. In certain breeds of domestic pigeon, genetic mapping and developmental studies show that regulatory changes in two genes that control limb-type identity (fore- or hindlimb) and outgrowth are associated with the replacement of scales by feathers on the feet. These changes in the skin are accompanied by defects in muscle and tendon patterning, thereby demonstrating that this phenotype is not limited to epidermal appendages. In humans, mutations in these same genes cause striking limb malformations, including clubfoot, Holt-Oram syndrome, and Liebenberg syndrome. This project seeks to understand how these genes function to specify tissue identity (e.g., scales or feathers) and regulate patterning of lim musculature. The pigeon is an ideal system in which to pursue these goals because it features tremendous morphological variation within a single species, thereby facilitating genome-wide association studies, traditional genetic mapping, and functional developmental biology. This project will pursue three separate aims. Aim 1 will identify cis-regulatory mutations in the two genes associated with transformations in limb-type identity. Enhancer mutations will be fine-mapped using a combination of whole-genome resequencing of breed with foot feathers ("muffs"), and massively parallel chromatin immunoprecipitation sequencing (ChIP-seq) to identify enhancer activity. The impact of candidate mutations will be tested using in ovo reporter assays. Aim 2 will determine the gene regulatory network governing skin appendage fate. This aim will employ embryonic tissue transplantation experiments and high-throughput RNA sequencing to determine how and when hindlimb skin identity is specified. Aim 3 will determine the functional impact of changes in limb-type gene expression on muscle and skin patterning. This aim will test the contributions of the two candidate genes to hindlimb skin and muscle mis- patterning in an F2 intercross. Additionally, experimental embryonic manipulations will determine whether specific regulation of these genes is necessary for normal hindlimb muscle pattern and epidermal appendage fate. Together, these complementary genetic, genomic, and developmental approaches will identify the molecular basis of astonishing variation in an innovative model system, thereby opening new avenues to understand the roles of specific genes in normal and disease variation among vertebrates in general.

 描述(申请人提供)：了解解剖学变异的分子基础是生物学中的一个基本挑战。在某些情况下，控制人类解剖缺陷的基因反而是其他物种正常变异的基础；因此，全面了解多样性的一般分子机制有助于更好地了解人类健康。在某些品种的家鸽中，基因图谱和发育研究表明，控制四肢类型识别(前肢或后肢)和生长的两个基因的调控变化与脚部羽毛取代鳞片有关。皮肤的这些变化伴随着肌肉和肌腱图案的缺陷，从而表明这种表型并不局限于表皮附件。在人类中，这些基因的突变会导致严重的肢体畸形，包括马蹄内翻足、Holt-Oram综合征和Liebenberg综合征。该项目试图了解这些基因如何发挥功能来指定组织特性(例如，鳞片或羽毛)并调节LIM肌肉系统的模式。鸽子是实现这些目标的理想系统，因为它具有单一物种内巨大的形态变异，从而促进了全基因组关联研究、传统遗传图谱和功能发育生物学。这个项目将追求三个不同的目标。目标1将确定与肢体类型身份转换相关的两个基因中的顺式调节突变。增强子突变将使用带有足部羽毛的品种的全基因组重新测序和大规模平行染色质免疫沉淀测序(CHIP-SEQ)相结合的方法来精细绘制，以确定增强子的活性。候选突变的影响将使用OVO报告分析进行测试。目的2将决定决定皮肤附属物命运的基因调控网络。这一目标将利用胚胎组织移植实验和高通量RNA测序来确定如何以及何时指定后肢皮肤身份。目的3将确定肢体类型基因表达的变化对肌肉和皮肤图案的功能影响。这一目标将测试两个候选基因在F2杂交中对后肢皮肤和肌肉错误模式的贡献。此外，实验性的胚胎操作将决定这些基因的特定调控是否对正常的后肢肌肉模式和表皮附属物的命运是必要的。总之，这些互补的遗传、基因组和发育方法将在一个创新的模型系统中识别惊人变异的分子基础，从而开辟新的途径来了解特定基因在脊椎动物正常和疾病变异中的作用。